Boltzmann distribution

A certain particle is interacting with a reservoir at 500 k and can be in any four possible states. The ground state has energy 3.1 eV and three excited states all have the same energy. what is the probability that the particle is in ground state? what is the probability that the particle is in a particular excited state? what is the probability that it is in a state of energy -3.0 eV? using Boltzmann distribution